This feature has already been implemented, or is already achievable with existing methods.

I have seen a lot of attempts at rotating a mob(or object) based on the person's mouse coordinates. While this is a neat trick that would improve quality in a lot of Action games(or any game that it is necessary in), it is also detrimental on the server - in a way. There could probably be a solution to this, I don't know how but I'm pretty sure it can be incorporated.

Two built-in variables for handling the mouse's x and y location.

var mouse_x = 0;var mouse_y = 0;

A function that retrieves the mouse_x and mouse_y location and then changes the image based on that angle.

angle = mouse_direction(mouse_x, mouse_y)

Instead of having people making their own ways of doing this, which will probably hurt the server some how depending on how it's coded, this should be incorporated in the language as a built-in tool developers can use.